Neck Sizing

Brass doesn't usually fully form to the chamber after a single firing. If the fired, empty case easily goes into the chamber with the bolt closed then there is no reason to push the shoulders back. After a few firings I'd suggest carefully measuring the case and set dies to reduce shoulder length by .002-.003". Full length sizing keeps thing consistent from shot-to-shot until the brass life is exhausted.

Personally, I've had very good luck using FL bushing dies but the current trend seems to be the use of an expander mandrel after sizing. I've just never found the need to.

As a new reloader you should keep things simple and stick to the basics. Trying to master the many idiosyncrasies of precision reloading can only lead to confusion.

Good luck and see your counselor often because reloading is highly addictive. 😁
 
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I watched this before and thought to myself "can I accomplish this without the Redding shellholder set?" All the vendors in Canada are out of stock. Could I just dial in the sizing die a hair?
Yes, I only have the comp shell holder set for 338 lapua, I set up all my other dies by just screwing down the die more.
 
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After years of messing around with different ways to size my fired brass this is what I'm doing now. No more standard full length dies. They work your necks way more than needed.Up too .010 or more. Bushing dies let you chose the amount you squeeze the neck. You can pick a bushing that sets .0015 neck tension or one that sizes it's .004 under and then open it up with a mandrel. A quality bushing full length die in conjunction with Redding competition shell holders allow you to repeat the sizing operation over and over with very consistent results. A bonus is your brass will last longer.
 
Go slowly! Take your time, and only add one new step in your procedures until you are comfortable with all of it. I started wiht aLee PRcsision set, it was great, and now I am using match grade busing dies and they keep everything pretty much where I want. When it seems to be the right time (experience kinda tells you) I Fl resize, then do a re-zero with those rounds to get the cases expanded and proceed as usual. USE GOOD BRASS. Have fun, and be safe!!!!!
 
Ah yes -- the old "full length or neck only" question. You've come to the right place to hear a lot of opinions.

Starting out with the lowest possible investment is good in my estimation, especially if your wife is wondering why this new-found hobby is costing so much. So here's my take on it:

A Lee press is probably not the place to start, but it will do for now. I used one long ago, and I found it looser and sloppier than more expensive ones. So think about each equipment purchase as "best possible for tightness of fitment and intended length of service."

As for neck sizing, there are two things (at least) that you are correcting for when sizing: returning the neck to its original size and shape, and returning the case to its original length. Each firing (and you did not say now often you shoot your brass) will slightly expand the brass. If you take a fired case and try to load it in an empty chamber, you will note that it (probably) goes it with more resistance than when new. That's because the dimensions have changed a little. If you have a micrometer you can measure this.

Dimensions of the neck are important for the grip on the bullet when the rifle goes off. If this is consistent, you'll have better repeatability.

Dimensions of the case shoulder (base to a datum line on the shoulder) will gradually get longer over repeated firings of a case. This is not affected by neck sizing. As an aside -- what is the datum line? It is a point on the shoulder that you can use to measure the case length with repeatability. People have measuring tools that allow you to measure this fairly accurately -- the Lock N Load by Hornady is probably the most common. You need a micrometer to use this tool.

If you have enough brass that you are only firing each piece two or three times, the shoulder bump is probably less important. If you are planning to shoot your brass until the primer pocket gets too large to hold a primer, you will want to full length resize, or at least find some way to "bump" the shoulder back about .002". You can do this with a full length resizing die or a shoulder bump die. In any case, you will probably want a case length comparator (Hornady LNL) and a micrometer to be able to do this repeatably.

Enjoy your new hobby!
 
Welcome aboard and you will get a lot of similar and different information. This RABBIT HOLE can be more like a tunnel to the pits of time and money hell if you let it. The only thing to always causes me caution is when anyone says the words "Need, must, have to, etc.". Immediately I stop and look deeper into the topic. Absolutely there are things you must do for safety sake, and reality is a lot of things may work for you or may not work for you. I would encourage you the most to keep written records (I have 3 ring binders) on what you do as this may be the biggest help down the road for you. I'm a freak and tend to do things to a stupid level when trying stuff. Bat crap crazy things like time myself throwing weighed charges against the electronic dispensers, shooting round after round through the same case to see how many it will take, never and every time annealing to see if it actually matters, and many many other stupid and dangerous things over the last 40+ years. Tamer Example....I never found one single full sized arrow I shot out of my single shot 20ga they just went out of sight almost instantly.
 
I watched this before and thought to myself "can I accomplish this without the Redding shellholder set?" All the vendors in Canada are out of stock. Could I just dial in the sizing die a hair?
You could, that's the way I do. However after watching the video this would be the easiest way to set up dies consistently for a shoulder bump. If you have say a few cartridges requiring the same casehead then it could be worth it. That is if you shoulder bump, such as I do.
 
The Lee Seat die, with the sliding sleeve, like the Bonaza/Forster, is golden. The collet neck sizing die is great for staightening necks on new or new to you and damaged cases. It is nearly impossible to get consistent neck tension with the mandrel die. I have tried and I have a dial indicator on my K&M arbor press when seating with Wilson seating dies to measure neck tension. What the 1000 yard "F" class and 600 yd benchrest crowd are using, is the Full Length Redding Type "S" bushing die (used without the button). The shoulder bump is adjusted with the Redding Competition Shellholder set. You will want to hold the shoulder bump to that which allows reliable clambering in all weather conditions for hunting. The neck tension is tuned to (in my case and applications to one and a half thousandths) with the bushings and inside mandrels. This is the state o the art.

I show a group shot in freezing weather recently, with a factory barreled CMMG .224 Valkyrie at 540 yards with two magazines of three. II have also learned that weight sorting cases shrinks groups.
 

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